1897. _Evotomys nivarius_ Bailey, Proc. Biol. Soc. Washington,
11:136, May 13, type from northwest slope of Mount Ellinor, 4000
ft., Olympic Mts., Mason County, Washington.
The red-backed mouse of the Olympic Peninsula was originally accorded
specific rank. Currently it stands in the literature as a subspecies of
the wide-spread species _Clethrionomys gapperi_ because Dalquest (Univ.
Kansas Publ. Mus. Nat. Hist., 2:343, April 9, 1948) used the
name-combination _Clethrionomys gapperi nivarius_. Taylor and Shaw had
earlier (Occas. Papers Charles R. Conner Mus., 2:23, 1929) indicated
the same status by using the name _Evotomys gapperi nivarius_. Davis
(The Recent Mammals of Idaho, The Caxton Printers, Caldwell, Idaho, p.
306, April 5, 1939), however, indicated that the affinities of
_nivarius_ were with the _californicus_ [= _occidentalis_] group,
although he treated _nivarius_ as a distinct species. We have examined
two adult females (K. U. Nos. 10707 and 10708) of _nivarius_ from
Reflection Lake, 3800 ft., Jefferson County, Washington, and on the
basis of their thick, instead of thin, pterygoid processes concur with
Davis that the affinities of _nivarius_ are with the named kinds of
_Clethrionomys_ now arranged as subspecies of _Clethrionomys
occidentalis_, rather than with the kinds now arranged as subspecies of
_Clethrionomys gapperi_. Although we are aware that Dalquest (_op.
cit._:101-102) did not find actual intergradation between _nivarius_
and _Clethrionomys occidentalis occidentalis_--a ten-mile gap separated
their ranges--we prefer to use the name combination _Clethrionomys
occidentalis nivarius_. In doing so we recognize that intergradation
ultimately may be found between the two species _C. occidentalis_ and
_C. gapperi_; in that event the name _gapperi_ will apply as the name
of the species because it has priority over _occidentalis_.
The following named kinds of _Clethrionomys_ are considered to be
subspecies of _Clethrionomys occidentalis_:
CLETHRIONOMYS OCCIDENTALS OCCIDENTALIS (Merriam).
1890. _Evotomys occidentalis_ Merriam, N. Amer. Fauna, 4:25,
October 8, type from Aberdeen, Chehalis County, Washington.
1894. _Evotomys pygmaeus_ Rhoads, Proc. Acad. Nat. Sci.
Philadelphia, p. 284, October 23, type from mouth of Nisqually
River, Pierce County, Washington.
1929. _Evotomys gapperi occidentalis_, Taylor and Shaw, Occas.
Papers Charles R. Conner Mus., Washington State College, 2:23.
1948. _Clethrionomys californicus occidentalis_, Dalquest,
Univ. Kansas Publ., Mus. Nat. Hist., 2:344, April 9.
CLETHRIONOMYS OCCIDENTALIS CALIFORNICUS (Merriam).
1890. _Evotomys californicus_ Merriam, N. Amer. Fauna, 4:26,
October 8, type from Eureka, Humboldt County, California.
CLETHRIONOMYS OCCIDENTALIS CAURINUS (Bailey).
1898. _Evotomys caurinus_ Bailey, Proc. Biol. Soc. Washington,
12:21, January 27, type from Lund, east shore of Malaspina
Inlet, British Columbia.
1935. _Clethrionomys gapperi caurinus_, Racey and Cowan, Rept.
British Columbia Prov. Mus. for 1935, p. H 25.
CLETHRIONOMYS OCCIDENTALIS MAZAMA (Merriam).
1897. _Evotomys mazama_ Merriam, Proc. Biol. Soc. Washington,
11:71, April 21, type from Crater Lake, 7000 ft., Mount Mazama,
Klamath County, Oregon.
1936. _Clethrionomys californicus mazama_, Bailey, N. Amer.
Fauna, 55:192, August 29.
CLETHRIONOMYS OCCIDENTALIS NIVARIUS (Bailey).
1897. _Evotomys nivarius_ Bailey, Proc. Biol. Soc. Washington,
11:136, May 13, type from northwest slope of Mount Ellinor,
4000 ft., Olympic Mts., Mason County, Washington.
CLETHRIONOMYS OCCIDENTALIS OBSCURUS (Merriam).
1897. _Evotomys obscurus_ Merriam, Proc. Biol. Soc. Washington,
11:72, April 21, type from Prospect, 2600 ft., upper Rogue
River Valley, Jackson County, Oregon.
1933. _Clethrionomys mazama obscurus_, Grinnell, Univ.
California Publ. Zool., 40:185, September 26.
1936. _Clethrionomys californicus obscurus_, Bailey, N. Amer.
Fauna, 55:192, August 29.